1. Field of the Invention
The present invention relates to a rotary compressor and, more particularly, to a variable discharge rotary compressor useful to compress refrigerant gas in an automotive air conditioner.
2. Description of the Prior Art
In recent years, compressors have been proposed which are operative to vary the discharge rate so as to reduce the power needed to drive the compressors while providing pleasant air conditioning. One method to vary the discharge rate of a compressor is to provide a bypass through which the refrigerant gas being compressed in a working chamber when in its compressor at a controlled rate. In the conventional rotary compressors, however, it has been difficult to provide the return bypass passages.
More specifically, the conventional type of rotary compressors is arranged such that the working chamber when in its compression stroke is positionally remote from the intake side of the compressor. Thus, the bypass passage is required to have a considerable length. In consequence, the refrigerant gas being returned through the bypass passage towards the intake side of the compressor is disadvantageously heated by the heat of the compressor body. When the heated gas is returned to the intake side of the compressor, the temperature of the refrigerant gas to be sucked into the compressor is raised to adversely affect the performance and durability of the compressor.